The chart features 20 congressional candidates who spent at least $35 per vote and includes the amount each one spent per eligible voter:

Some observations:

* At the top of the chart are two members of Congress who spent more than $100 per vote: Reps. Michele Bachmann (R-Minn.) and Allen West (R-Fla.). Bachmann spent more than $140 per eligible voter in her district, while West spent over $108 per voter in his district. No one else on the chart even cracks $65 per eligible voter. Both Bachmann and West competed in very tight contests (Bachmann narrowly won, while West was edged out by Democrat Patrick Murphy), and both were on our list of the best fundraisers of 2012.

* Spending big does not guarantee a win: Ten of the 20 candidates on the chart lost.

* The cost of competing in the Montana Senate race was high. The state is not very populous and doesn't contain the kind of huge media markets that attract top advertising dollars elsewhere. So, dollar for dollar, it was outpaced by several other races. But it was the only Senate race in which both the Democratic and Republican nominees ended up on the Sunlight Foundation chart.

Sean Sullivan has covered national politics for The Washington Post since 2012.

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